Serena Williams talks the talk after walking the walk at Wimbledon

APSerena Williams serves a ball to Russia's Maria Kirilenko during their match at Wimbledon.

WIMBLEDON, England -- Serena Williams has been known to say she isn't satisfied with this or that aspect of her game, even after easily winning a match, say, 6-3, 6-2.

So it was somehow refreshing to hear Williams actually praise herself after a victory by that very score over 26th-seeded Maria Kirilenko at Wimbledon on Saturday.

Yes, only five matches since returning to the tour after nearly a full year off because of a series of health scares, Williams produced a performance worthy of the 13-time Grand Slam champion that she is. And then Williams talked the talk of someone finally ready to concede that British bookmakers might very well have been right to make her the pre-tournament favorite.

Asked whether she was surprised by the odds, the seventh-seeded American smiled widely and said: "I wouldn't bet against me."

After hitting 10 aces and compiling a 32-9 edge in winners against Kirilenko, Williams termed the showing her "best I've played since I came back."

"I was a little more consistent, and I played my game more," said Williams, trying to become the first woman since Steffi Graf in 1991-93 to win three consecutive Wimbledon titles. "Wasn't as tight and nervous and uptight. I was able to relax more today."

She was part of a parade of past champions who breezed into the fourth round Saturday, joined by Roger Federer, Rafael Nadal and Maria Sharapova, who all were straight-set winners, too. Top-seeded Caroline Wozniacki, seeking her first Grand Slam title, and two-time Australian Open champion Novak Djokovic, who is now 44-1 in 2011, also moved on.

There were two upsets of some significance.

Two-time French Open finalist Robin Soderling, who was seeded fifth, was dealing with stomach problems and bowed out meekly against 158th-ranked qualifier Bernard Tomic of Australia 6-1, 6-4, 7-5. Tomic is the first 18-year-old to reach the men's fourth round at Wimbledon since Michael Chang and Goran Ivanisevic in 1990.

"I was very calm, but inside I was bursting. I tried not to show it to him. He was getting a bit frustrated," Tomic said. "The way I've been playing is really good. If I can keep it up like this, who knows?"

No. 9 Gael Monfils lost to 93rd-ranked qualifier Lukasz Kubot of Poland 6-3, 3-6, 6-3, 6-3. Kubot is the first man from Poland to make it this far at Wimbledon since Wojtek Fibak in 1981.

Wimbledon is the only Grand Slam tennis tournament that schedules a day off on the middle Sunday - and the only one that puts all 16 men's and women's fourth-round matches on the second Monday. When play resumes, these are some of the men's matchups: No. 1 Nadal vs. No. 24 Juan Martin del Potro, the 2009 U.S. Open champion; No. 2 Djokovic vs. No. 19 Michael Llodra; No. 3 Federer vs. No. 18 Mikhail Youzhny; No. 4 Andy Murray vs. No. 17 Richard Gasquet; and No. 10 Mardy Fish, the last U.S. man left, vs. No. 6 Tomas Berdych, the 2010 Wimbledon runner-up.

Fish advanced Saturday when Robin Haase retired in the fourth set, while Berdych wrapped up a rain-suspended victory over Alex Bogomolov Jr. of the United States.

"It's lonely," said Fish, who's been broken only once in three matches.

Djokovic trashed his racket during a 6-4, 4-6, 6-3, 6-4 victory over 2006 Australian Open finalist Marcos Baghdatis in the day's last match on Centre Court.

"Look, I'm not going to change who I am. I can work on some things, but, you know, my temper is my temper. My character is my character," said Djokovic, whose 43-match winning streak ended with a loss to Federer in the French Open semifinals.

With Baghdatis serving at 30-all while leading 4-3 in the second set, Djokovic pushed a shot long to lose the point. Standing at the baseline, he smashed his racket, hitting it once, twice, three times against the ground. As Djokovic walked to the sideline to trade in that now-damaged piece of equipment for a fresh one, Baghdatis chuckled to himself.

Chair umpire James Keothavong - brother of British player Anne Keothavong - was less amused, warning Djokovic for racket abuse. Baghdatis won the next point, too, to pull ahead 5-3, and he served out the set with an ace two games later.

But Djokovic pulled through, even as he occasionally paused to clutch at his left leg.

"I'm not tired physically. I just didn't feel good today. ... My legs weren't working. You have those days," Djokovic said. "Luckily for me, when I needed to, I played well."

Nadal also acknowledged being slightly bothered a muscle problem in his right leg during a 7-6 (6), 7-6 (5), 6-0 win over Gilles Muller of Luxembourg - the last man other than Federer to beat the Spaniard at Wimbledon. Nadal made a total of three unforced errors - and 30 winners - against Muller, who eliminated him in the second round in 2005.

Since then, Nadal is 29-2 at the grass-court Grand Slam tournament, losing to Federer in the 2006 and 2007 finals, then winning the titles in 2008 and 2010. Nadal skipped Wimbledon in 2009 because of tendinitis in his knees; he made clear Saturday his knees are fine now.

As for del Potro, a former top-five player who's seeded 24th as he works his way back from right wrist surgery that sidelined him most of last year, Nadal observed: "His level is much better than what the ranking says today."

The same goes for Williams, who is ranked only 25th. A few days after winning her fourth Wimbledon title last year, she cut both her feet on glass at a restaurant. That led to two operations on her right foot; she later was hospitalized for clots in her lungs, and then to remove a pool of blood that gathered under the skin on her stomach.

Understandably, she explained Saturday, she'd been playing tentatively until Saturday.

"You're always thinking, 'I can get hurt again.' You just kind of have to let those thoughts go or anything could happen," Williams said. "And I wasn't thinking that at all today. It was just a big difference."

After beating Kirilenko - her first straight-set victory in five matches since returning - Williams revealed another, if less serious, mishap from her annus horribilis: She scraped her right shoulder and face when she fell off her pink bicycle during a ride near her home in Florida in October.

"I'm thinking, 'Oh, nooooooo,'" Williams recounted, as though replaying her words in slow motion. "All I thought was, 'Don't fall on my face. Don't fall on my face.' When I fell on my face, I was like, 'No!'"